[PATCH 1/2] fixup! stdio: stub out basprintf and friends when built for PBL

[PATCH 1/2] fixup! stdio: stub out basprintf and friends when built for PBL

[Ahmad Fatoum]

asprintf and vasprintf return only -1 as error code, so have the stub
follow suit for symmetry.

No functional change expected.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 include/stdio.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/stdio.h b/include/stdio.h
index 03cd3d281890..883b06529fdc 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -32,7 +32,7 @@ static inline char *basprintf(const char *fmt, ...)
 }
 static inline int asprintf(char **strp, const char *fmt, ...)
 {
-	return -ENOMEM;
+	return -1;
 }
 static inline char *bvasprintf(const char *fmt, va_list ap)
 {
@@ -40,7 +40,7 @@ static inline char *bvasprintf(const char *fmt, va_list ap)
 }
 static inline int vasprintf(char **strp, const char *fmt, va_list ap)
 {
-	return -ENOMEM;
+	return -1;
 }
 #endif
 
-- 
2.39.5

[PATCH 2/2] fixup! stdio: stub out basprintf and friends when built for PBL

[Ahmad Fatoum]

vsprintf: fix false positive about use of uninitialized variable

barebox vasprintf only writes to its strp argument, when a buffer could
be allocated. If out of memory (or in PBL without malloc), -1 is
returned after vsnprintf determines the length.

GCC 13.1.1 seems not able to track use of strp across vsnprintf
correctly though resulting in a bogus warning:

  ./lib/vsprintf.c: In function 'bvasprintf':
  ./lib/vsprintf.c:961:16: warning: 'p' may be used uninitialized
                           [-Wmaybe-uninitialized]
    961 |         return p;
        |                ^

Fix this by adding an explicit early exit for the PBL case.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 lib/vsprintf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index e421a4352a12..edc3f4aa4fe0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -933,6 +933,10 @@ int vasprintf(char **strp, const char *fmt, va_list ap)
 	va_list aq;
 	char *p;
 
+	/* Silence -Wmaybe-uninitialized false positive */
+	if (IN_PBL)
+		return -1;
+
 	va_copy(aq, ap);
 	len = vsnprintf(NULL, 0, fmt, aq);
 	va_end(aq);
-- 
2.39.5

Re: [PATCH 1/2] fixup! stdio: stub out basprintf and friends when built for PBL

[Sascha Hauer]

On Mon, Dec 02, 2024 at 12:37:28PM +0100, Ahmad Fatoum wrote:
> asprintf and vasprintf return only -1 as error code, so have the stub
> follow suit for symmetry.
> 
> No functional change expected.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  include/stdio.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/include/stdio.h b/include/stdio.h
> index 03cd3d281890..883b06529fdc 100644
> --- a/include/stdio.h
> +++ b/include/stdio.h
> @@ -32,7 +32,7 @@ static inline char *basprintf(const char *fmt, ...)
>  }
>  static inline int asprintf(char **strp, const char *fmt, ...)
>  {
> -	return -ENOMEM;
> +	return -1;
>  }
>  static inline char *bvasprintf(const char *fmt, va_list ap)
>  {
> @@ -40,7 +40,7 @@ static inline char *bvasprintf(const char *fmt, va_list ap)
>  }
>  static inline int vasprintf(char **strp, const char *fmt, va_list ap)
>  {
> -	return -ENOMEM;
> +	return -1;
>  }
>  #endif
>  
> -- 
> 2.39.5
> 
> 
> 

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